Understanding Simmerring Performance Limits

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The discussion focuses on the performance limits of Simmerring seals based on shaft diameter and circumferential speed. With a shaft diameter of 20 mm and a rotational speed of 1370 rpm, calculations indicate a circumferential speed of 1.5 m/s. The permissible speeds for using NBR and FKM materials are outlined in a referenced graph, which categorizes operational limits into light gray, dark gray, and blue regions. The light gray region allows for the safe use of NBR, while both light and dark gray regions permit the use of FKM. Understanding these limits is crucial for selecting the appropriate sealing material for optimal performance.
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The diameter of the shaft is 20 mm, and the circumferencial speed is 1,5 m/s, which i calculated doing

velocity = angular speed * shaft radius

The shaft rotates at 1370 rpm.

The graph should give the permissible speeds for the shaft to rotate at that allow the use of the simmerring made of that material. NBR and FKM are two materials from which their simmerings are made.

Source: http://www.simrit.com/files/00001387.pdf , p.20
 
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The rpm lines are there as a convenience so you don't have to do the calculation you did yourself.

If your case is in the light gray region (which it is), you can safely use the NBR material. If it is in the dark gray region (and I presume the light gray region as well), you can use the FKM material. You cannot use either of them if you are in the blue region.
 
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Ahhh got it ! thank you very much
 
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